Webpack Plugin

/**
 * Creates a new BundleAnalyzerPlugin instance
 * @param options - Plugin configuration options
 */
class BundleAnalyzerPlugin {
  constructor(options?: BundleAnalyzerOptions);
  apply(compiler: object): void;
}

interface BundleAnalyzerOptions {
  /** Analysis mode: server starts HTTP server, static generates HTML file, json creates JSON report, disabled only generates stats */
  analyzerMode?: 'server' | 'static' | 'json' | 'disabled';
  /** Host for HTTP server in server mode */
  analyzerHost?: string;
  /** Port for HTTP server in server mode, 'auto' for automatic assignment */
  analyzerPort?: number | 'auto';
  /** Custom URL generation function for server mode */
  analyzerUrl?: (options: { listenHost: string; listenPort: number; boundAddress: object }) => string;
  /** Output filename for static and JSON modes, relative to webpack output directory */
  reportFilename?: string;
  /** Report title, can be string or function returning string */
  reportTitle?: string | (() => string);
  /** Default size type to display in visualization */
  defaultSizes?: 'stat' | 'parsed' | 'gzip';
  /** Whether to automatically open report in browser */
  openAnalyzer?: boolean;
  /** Whether to generate webpack stats JSON file */
  generateStatsFile?: boolean;
  /** Filename for webpack stats JSON file */
  statsFilename?: string;
  /** Options passed to stats.toJson() method */
  statsOptions?: object;
  /** Patterns to exclude assets from analysis */
  excludeAssets?: string | RegExp | ((assetName: string) => boolean) | Array<string | RegExp | ((assetName: string) => boolean)>;
  /** Logging level for plugin output */
  logLevel?: 'info' | 'warn' | 'error' | 'silent';
  /** Whether to start analyzer server (deprecated, use analyzerMode instead) */
  startAnalyzer?: boolean;
}

const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');

// Basic usage with default options
module.exports = {
  plugins: [
    new BundleAnalyzerPlugin()
  ]
};

// Server mode with custom port
module.exports = {
  plugins: [
    new BundleAnalyzerPlugin({
      analyzerMode: 'server',
      analyzerHost: 'localhost',
      analyzerPort: 9999,
      openAnalyzer: true
    })
  ]
};

// Static report generation
module.exports = {
  plugins: [
    new BundleAnalyzerPlugin({
      analyzerMode: 'static',
      reportFilename: 'bundle-report.html',
      openAnalyzer: false
    })
  ]
};

// JSON report with stats file
module.exports = {
  plugins: [
    new BundleAnalyzerPlugin({
      analyzerMode: 'json',
      reportFilename: 'bundle-report.json',
      generateStatsFile: true,
      statsFilename: 'webpack-stats.json'
    })
  ]
};

/**
 * Applies the plugin to webpack compiler
 * @param compiler - Webpack compiler instance
 */
apply(compiler: object): void;

// Asset filter pattern types
type AssetFilterPattern = 
  | string              // Converted to RegExp
  | RegExp              // Used directly for matching
  | ((assetName: string) => boolean);  // Custom filter function

// Multiple patterns
type ExcludeAssets = AssetFilterPattern | AssetFilterPattern[];

// Exclude by string pattern (converted to RegExp)
new BundleAnalyzerPlugin({
  excludeAssets: 'vendor'
});

// Exclude by RegExp
new BundleAnalyzerPlugin({
  excludeAssets: /\.(css|png|jpg|gif)$/
});

// Exclude by custom function
new BundleAnalyzerPlugin({
  excludeAssets: (assetName) => assetName.includes('legacy')
});

// Multiple exclusion patterns
new BundleAnalyzerPlugin({
  excludeAssets: [
    'vendor',
    /\.css$/,
    (assetName) => assetName.startsWith('runtime.')
  ]
});

type AnalyzerMode = 'server' | 'static' | 'json' | 'disabled';

type SizeType = 'stat' | 'parsed' | 'gzip';

type ReportTitle = string | (() => string);

// Static title
new BundleAnalyzerPlugin({
  reportTitle: 'My App Bundle Analysis'
});

// Dynamic title with current date
new BundleAnalyzerPlugin({
  reportTitle: () => `Bundle Analysis - ${new Date().toLocaleDateString()}`
});

// Using built-in default title function
const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');
const utils = require('webpack-bundle-analyzer/lib/utils');

new BundleAnalyzerPlugin({
  reportTitle: utils.defaultTitle
});